From my perspective, this seems like an easy decision: go for the MPA. 1) It provides a more direct route to your professional goals. 2) No debt. 3) It is in the area you want to work in, so you will be making relevant connections in your program. These are all huge considerations.
I do think that name recognition and prestige are less primary concerns in social welfare fields.
You could consider doing a graduate certificate in social justice in addition to the MPA. I found this, for instance: https://priceschool.usc.edu/programs/certificate/social-justice/

So I'm a long time Chicago resident, but I haven't spent a ton of time in Hyde Park, where I'll likely be attending UChicago. I know about Medici, Seminary Co-op, Salonica, and the Regenstein-- are there any out of the way places I should know about for studying/hanging out? Preferably quiet and with good vibes.
In terms of commute, I'm in Ukrainian Village, and it looks like I'll be slogging it on the green line for an hour and 15 mins each way (ick). Is there really not an intercampus shuttle from downtown or anything like that? Just checking. And any commute tips in general would be welcome.

I would echo @lincoln.hawks and say don't sell yourself short. This season is my first applying to graduate programs and so far I've been accepted to University of Chicago with a 3.14 undergrad GPA (major GPA around 3.5). I graduated from a small lib arts college in 2013 and have no clinical experience, but some experience more tangentially related to social services.
I think my statement of purpose and letters of recommendation were very strong. I also took several post-bacc courses in psychology this year and received all A's; in one course in particular I excelled and received a great rec from the professor.
I was thrilled, and admittedly surprised, to be admitted to UChicago (my top choice). It taught me that GPA is just one factor, and a potentially small one at that. The scholarship they offered me was on the lower end of the spectrum, which makes sense to me. But I am low-income and a first generation college grad, so I'm hoping for some significant need-based aid.
Basically, my undergraduate record does not reflect my current abilities or state of mind, and I think I managed to effectively convey that in my application (not that I directly addressed my GPA). I think I made my personal growth clear to see. I think I am also genuinely a good fit for UChicago's program.
Especially since it sounds like you have some great work experience under your belt, I would not worry, but rather focus on crafting a high quality, sincere statement of purpose.

I want to pursue clinical casework. I'm not exactly sure in which setting yet, but a few interests are: independent organizations that monitor prison conditions, prisons/jails themselves, organizations that assist incarcerated or recently incarcerated individuals, hospitals, and inpatient psychiatric wards. My general population interest is people with mental illness.
But, I like that with a social work degree (especially the one I'll likely be pursuing at UChicago) I'll have the option to explore non-profit administration/ leadership roles if I want to. For example, if clinical work ends up being too emotionally overwhelming, I could pivot to non-clinical roles. My partner is an LPC and I am intimately familiar with the burnout and compassion fatigue that can accompany clinical work. I hope this won't be the case for me-- and I feel strongly that being a clinician is my calling-- but I'm glad to have that amount of flexibility, which I wouldn't quite have with, say, a counseling degree. I also feel like it's possible that I might do both kinds of work at different points in my career, or even simultaneously, who knows?
I'm not ruling out psychotherapy or private practice. My background and interests are actually pretty psychodynamic (I wrote my undergrad thesis on Jung and have a long-term interest in depth psychology). Overall, I just feel like a social work degree offers a lot of versatility and that really appeals to me.
If you're positive you want to be a therapist, there are of course a lot of great counseling MA programs out there to look into. I think it just depends on your goals and, to some extent, the types of clients you want to work with. I specifically want to work with people who need help the most, many of whom might be too severely ill or lack the resources for traditional psychotherapy. A lot of people would prefer to work with higher functioning clients, and the nature of that work is quite different.
Just my impressions, I'm by no means an expert! Still figuring this stuff out too.

Ah, thank you! That's reassuring. I'm determined to make it work, but wasn't sure if there was the possibility of more need-based scholarships, or if that was already incorporated in the initial scholarship offer that came with admission. I'll probably start researching external scholarships too, hopefully too many deadlines haven't passed yet... thanks again!

Does anyone know what the need-based financial aid packages might look like? Is that just loans or are there also need-based scholarships available? I am low-income. I'll probably call the school on Monday, but wondering if anyone here has insight.

I applied to:
University of Chicago SSA
University of Washington Seattle
Portland State University
I've been accepted to University of Chicago with a merit-based scholarship that I wish was a bit higher, but I'm hoping that the forthcoming need-based scholarship info will be helpful. Still waiting to hear back from UW and Portland, but SSA is my top choice.
I'm a bit of a non-traditional applicant. I'm 28 and graduated with a B.A. in Humanities in 2013 from a small liberal arts college. My GPA was lackluster (3.14) due to mental health issues. My major GPA was around 3.5.
This Spring I took several psychology courses at Northwestern, and got all A's. My statement of purpose for UofC was strong and sincere. I think I also had very good recommendations, one of which was from my Psychopathology professor at Northwestern. I've had jobs that are tangentially related to social services, but no clinical experience.
I was really concerned about my GPA! Enough that I put off applying to graduate school for years out of fear of not getting in anywhere. So if anyone is reading this in a similar situation... have hope! I know that I could have used some hope a bit earlier in the game.

I didn't end up applying to UIC, although it is by far the most affordable option in Chicago, because it seemed to require a stats course prior to applying.
I haven't taken stats and did not want to invest time and money into a prerequisite for a program I may or may not be admitted to. That was my reasoning at the time.
In retrospect, I think it probably would have been a good idea (if I had started planning a bit sooner), especially since the stats course would have benefited my other applications as well.
At any rate, that's in the past now-- anxiously waiting these SSA decisions! ?
Hope everyone is hanging in there, and congrats to the advanced standing peeps already admitted!